Vortex-induced vibration simulation test device for deep sea riser model with movable top end under action of step flow

The invention discloses a vortex-induced vibration simulation test device for a deep sea riser model with a movable top end under the action of step flow, relates to the technical field of the oceanographic engineering and solves the technical problem of simulating the vortex-induced vibration of a deep sea riser under the action of the step flow. The device comprises a towing tank, a trailer, a deep sea riser module, a top supporting module, a bottom supporting module, vertical rail modules, a horizontal rail module, a sleeve module and a measurement analysis control module. The horizontal rail module is hung on the trailer. Two vertical rail modules are provided and are respectively and vertically hung on the horizontal rail module. The top supporting module and the bottom supporting module are respectively arranged on the two vertical rail modules and are both provided with acceleration transducers. A sleeve part in the sleeve module is sleeved on the periphery of the riser model of the deep sea riser module. The measurement analysis control module is connected with each fiber grating sensor, each acceleration transducer and each motor. The device provided by the invention can be used for simulating the vertex-induced vibration of the deep sea riser under the action of the step flow.